My heart goes out to you. Just this past July we finally had to have our beloved 16 year old Schnoodle euthanized. We had been battling his kidney disease for 3 1/2 years. And the kidney disease plus his old age finally took their toll. I know how heartbreaking the loss of a beloved pet can be. Here's a link to my favorite article, from PC's archives, on healing from the loss of a pet:

What My Dog Taught Me about Grief and Loss

Best wishes...